when i read the thing i was thinking of a guild with focuses on
a) ranged combat -- archery, possibly ranged spells

light armor
c) summoning magic, maybe magic that summons normal creatures as oppposed to demonic ones
d) some sneaking and theaving, but more outdoors sort of stuff. like maybe quests where they have to track someone and follow them to their guild without them noticing
e) alchemy, they'd gather what they need from the woods
f) hunting, not only regular animals but rare ones that would be added to the game.
g) ambushes. imagine setting up an ambush for a fighter or mages guild caravan and jumping at them out of trees, off of rocks, out of crevices, etc. and just tearing them up with a barrage of arrows.
i think it could work if you came up with enough good ideas for quests and skill perks, etc.